Fluid-cooled heat shield and system

ABSTRACT

A fluid-cooled heat shield and closed loop system is provided to continuously transfer heat away from an object or area to be cooled. The system utilizes a coolant fluid that is pumped through the system by a circulating pump. Heat from a heat source is conveyed to a heat conductor shield and then to a heat sink and transferred by convection to the coolant fluid. The coolant fluid is pumped to a radiator where a fan is used to help transfer heat from the fluid and into the ambient air. The cooled water is then recirculated to the heat sink. The shields may be configured as mats and may be used flat or wrapped around an object to be cooled.

This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/569,539, filed May 10, 2004, herein incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to specialized heat exchangers and, more particularly, to a fluid-cooled heat shield and system used to transfer heat from a first location to a second location and having applications particularly suited to vehicles and, in particular, endurance race cars.

BACKGROUND OF THE INVENTION

A serious problem for race car drivers is the heat that enters the cockpit through the footwell of the vehicle. The vehicle's exhaust collectors are typically located directly below the driver's footwell or floor pan such that the heat travels directly into the driver's cockpit. The elevated temperatures are such that many drivers have burned portions of their feet and especially their heels during the course of the race. In addition, the temperature of the cockpit increases to an intolerable and, possibly dangerous, level if it can distract the driver from the race.

Many prior art attempts have been made to try to lower the cockpit/footwell temperature, however, a suitable light-weight, effective, and low cost solution has yet to be found. One problem with the prior art has been that the hot areas or heat sources are merely shielded. Over a prolonged race, the heat merely builds up and overcomes or lessens the effectiveness of the shielding. One prior art shielding product boasts that their product has the ability to lower the floor pan temperature from 750° F. to 380° F. This lower temperature is still too hot and will burn the driver's feet over an extended race.

Accordingly, there is a need for a heat shield that is able to constantly remove the heat to the ambient environment without allowing a constant unrelieved heat build-up on the shield.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a fluid-cooled heat shield comprising a conductive sheet layer, a facing sheet layer positioned on a first side of the conductive sheet and adapted to protect the conductive sheet layer while allowing heat transfer through the facing sheet, an insulating sheet layer positioned on a second side of the conductive sheet and adapted to prevent heat transfer from the second side of the conductive sheet to the insulating sheet layer, a heat sink conductively attached to the conductive sheet layer and positioned between the facing sheet layer and the insulating sheet layer, wherein the heat sink comprises a fluid inlet, a fluid outlet, and a fluid passageway, wherein heat from the conductive sheet layer and the heat sink is transferred to a fluid traveling through the fluid passageway.

Another embodiment of the present invention provides a closed-loop heat removal system for an automotive vehicle comprising a fluid-cooled heat shield comprising a heat sink conductively attached to a conductive sheet layer positioned between an insulating sheet layer and a facing sheet layer, a radiator, and a fluid pump adapted to move a heated fluid from the fluid-cooled heat shield to the radiator where the fluid is cooled.

The present invention provides a method of removing heat from a portion of a vehicle comprising the steps of providing a fluid-cooled heat shield comprising a heat sink conductively attached to a conductive sheet layer positioned between an insulating sheet layer and a facing sheet layer; positioning the facing sheet layer of the fluid-cooled heat shield toward a source of heat of the vehicle; pumping a fluid through the heat sink wherein heat from the conductive sheet layer and the heat sink is transferred to the fluid; and pumping the fluid through a radiator wherein the heat is transferred from the fluid to an ambient air.

These and other advantages will be apparent by reviewing the following specification and drawings.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a portion of the layers comprising the fluid-cooled heat shield of the present invention;

FIG. 2 is a perspective view of three different sized fluid-cooled heat shields of the present invention;

FIG. 3 is a plan view of a first embodiment of the conductive shield and heat sink of the present invention showing a fluid passage through the heat sink;

FIG. 4 is a cross-sectional view of a second embodiment of the conductive shield and heat sink of the present invention;

FIG. 5 is a cross-sectional view of the heat sink of FIG. 4 showing the fluid passageway grid providing optimized heat transfer between the fluid and the heat sink; and

FIG. 6 is a flow chart and related components of the fluid-cooled heat shield system of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to FIG. 1, the fluid-cooled heat shield 10 of the present invention is shown in a partial cross-sectional view. The fluid-cooled heat shield comprises a heat sink 20 having a fluid passageway 30 formed therethrough to promote convective heat transfer between the heat sink 20 and the fluid, typically water or any other suitable heat transfer fluid. The heat sink 20 may be comprised of a block of copper or aluminum or any other suitable material, preferably having a high thermal conductivity, but not necessarily limited as such. The fluid passageway 30 of the heat sink 20 may be anodized or otherwise treated to prevent corrosion from the coolant fluid. A conductive sheet or shield 40 is conductively attached to the heat sink 20 and extends outward away from the heat sink 20. The conductive sheet 40 is preferably comprised of a thin copper foil although alternative materials such as aluminum or any material with a suitably high thermal conductivity may be used. The conductive sheet 40 and the heat sink 20 are preferably made from the same material, however, the invention is not limited as such. Appropriate measures may be needed to prevent galvanic corrosion from dissimilar metals if different materials are used for the heat sink 20 and the conductive shield 40. The “hot side” (the side intended to face the source or direction of heat) of the conductive sheet 40 and the heat sink 20 are covered with a protective facing 50 which may be comprised of a Mylar fiberglass lamination or any other suitable material that allows the heat to pass through to the conductive sheet 40 and heat sink 20 and also protects and strengthens the thin foil of the conductive sheet 40. The protective facing 50 will also protect the conductive sheet 40 from moisture which may corrode many of the materials suitable for the conductive sheet 40. The opposite face side or “cool side” of the conductive sheet 40 and the heat sink 20 are covered by an insulating sheet 60. The insulating sheet 60 may be comprised of a high temperature silica or fiberglass felt or any other suitable material that will help ensure that the heat is not transferred to the cool or protected side of the fluid-cooled heat shield 10. The insulating sheet 60 is covered by a protective layer 70 which may be comprised of an aluminum foil fiberglass lamination or any other suitable material which will protect conductive sheet 40, heat sink 20, and insulating sheet 60. The protective layer 70 will also protect the conductive sheet 40 from moisture which may corrode many of the materials suitable for the conductive sheet 40. The protective layer 70 will also prevent moisture ingress to the insulating sheet 60 which would result in the moisture helping redirect the heat through the insulating sheet 60 and into the protected area beyond the fluid-cooled heat shield 10.

A series of different sized, fluid-cooled heat shields 10 are shown in FIG. 2 having fluid inlet tubes 12 and fluid outlet tubes 14 extending therefrom. The fluid-cooled heat shields 10 are formed as thin mats sized according to their particular application. The mats 10 can be placed directly below the driver's feet, on the outside of the cockpit, tied or wrapped around exhaust pipes, or placed as needed in the engine compartment. The mats 10 may include fastening apertures 16 at the corners to facilitate attachment of the mats in a particular location. The highly textured aluminum composite surface of protective layer 70 provides a durable and aesthetically pleasing look.

FIG. 3 shows a first embodiment of the conductive shield 40 and heat sink 20 of the present invention showing the fluid passageway 30 through the heat sink 20. The fluid passageway 30 is represented as a U-shaped loop. Fluid enters the heat sink 20 through the inlet 12 at a first temperature and is subjected to the elevated temperatures of the heat sink 20. Heat is transferred from the heat sink 20 to the fluid by convection and then leaves the heat sink 20 through the outlet 14. The heat sink 20 is typically formed as two pieces with the first member including the fluid passageway 30. A base plate or second member (not shown) is positioned on the opposite side of the conductive shield 40 and the first member is secured to the base member by fasteners 22 or the like.

A second embodiment of the heat sink 20′ of the present invention is shown in FIG. 4. In this embodiment, the simple “U” of the fluid passageway 30 is replaced by a more complex grid 32 and fluid passageway 30′ which greatly increases the contact surface area of the fluid and the heat sink 20′ resulting in a significant increase in the heat exchange transfer efficiency of the heat sink 20′. A side cross-sectional view is shown in FIG. 5 and shows the heat sink 20′ sandwiching the conductive shield 40. As shown, the conductive shield 40 forms the upper wall of the fluid passageway 30′ such that convection takes place directly with the conductive shield 40 at these locations. Although not shown, it is also contemplated that the conductive shield 40 may be positioned or surface treated such that it is not in direct contact with the fluid in order to prevent corrosion of the conductive shield 40.

It is contemplated that the fluid-cooled heat shield 10 is used as part of a closed loop cooling system 110 as shown in FIG. 6. System 110 comprises a fluid circuit between the fluid-cooled heat shield 10, a pump 112, a radiator 114 and an expansion tank 116. The fluid passes through these components and transfers heat collected at the fluid-cooled heat shield 10 to the radiator 114. A fan 118 is typically associated with the radiator to force air through the radiator and such that the heat is removed from the fluid and into the ambient air. The pump 112 keeps the fluid moving between components such that the heat is properly transferred. The fluid used will typically be water or a water based coolant material. Water is about twenty times more effective than air at removing heat from a body by convection. While water holds four times more heat than air, weight for weight, water is eight hundred times more dense than air. Accordingly, a small amount of water can hold much more heat than a large volume of air. This results in the system of the present invention being able to run component temperatures much closer to ambient with little temperature variation under varying heat loads.

It is contemplated that innumerable changes could be made to the configuration of the embodiments shown without departing from the intended scope of the invention. For example, different fluid passageways could be provided, multiple conductive shields could be employed with the heat sink, etc. The copper foil heat shield could be used with a conventional type of metal of any other prior art material that might increase the performance of the shield. Although the present invention has been described above in detail, the same is by way of illustration and example only and is not to be taken as a limitation on the present invention. 

1. A fluid-cooled heat shield comprising: a conductive sheet layer; a facing sheet layer positioned on a first side of the conductive sheet and adapted to protect the conductive sheet layer while allowing heat transfer through the facing sheet; an insulating sheet layer positioned on a second side of the conductive sheet and adapted to prevent heat transfer from the second side of the conductive sheet to the insulating sheet layer; a heat sink conductively attached to the conductive sheet layer and positioned between the facing sheet layer and the insulating sheet layer; wherein the heat sink comprises a fluid inlet, a fluid outlet, and a fluid passageway, wherein heat from the conductive sheet layer and the heat sink is transferred to a fluid traveling through the fluid passageway.
 2. The fluid-cooled heat shield of claim 1 further comprising an outer protective sheet layer positioned on a side of the insulating layer opposite the conductive sheet layer.
 3. The fluid-cooled heat shield of claim 1, wherein the conductive sheet layer is a thin foil made of a conductive metallic material.
 4. The fluid-cooled heat shield of claim 1, wherein the conductive sheet layer is at least partially copper or aluminum.
 5. The fluid-cooled heat shield of claim 1, wherein the heat sink is made of a conductive metallic material.
 6. The fluid-cooled heat shield of claim 1, wherein the insulating sheet layer is a high temperature silica or fiberglass felt.
 7. The fluid-cooled heat shield of claim 2, wherein the outer protective sheet layer is made of an aluminum foil fiberglass lamination.
 8. The fluid-cooled heat shield of claim 1, wherein the protective facing is a Mylar fiberglass laminate.
 9. The fluid-cooled heat shield of claim 1, wherein the fluid passageway of the heat sink is “U” shaped or in the form of a grid.
 10. The fluid-cooled heat shield of claim 1 further comprising at least one fastening aperture through at least the facing sheet layer and the insulating layer.
 11. A closed-loop heat removal system for an automotive vehicle comprising: a fluid-cooled heat shield comprising a heat sink conductively attached to a conductive sheet layer positioned between an insulating sheet layer and a facing sheet layer; a radiator; and a fluid pump adapted to move a heated fluid from the fluid-cooled heat shield to the radiator where the fluid is cooled.
 12. The closed-loop heat removal system of claim 11 further comprising an expansion tank for allowing the thermal expansion of the heated fluid.
 13. The closed-loop heat removal system of claim 11, wherein the radiator further comprises a fan.
 14. The closed-loop heat removal system of claim 11 wherein the fluid-cooled heat shield is positioned in a footwell of the automotive vehicle.
 15. The closed-loop heat removal system of claim 11, wherein the radiator is positioned in the vehicle at a location open to ambient air.
 16. The closed-loop heat removal system of claim 11, wherein the fluid-cooled heat shield further comprises an outer protective sheet layer positioned on a side of the insulating layer opposite the conductive sheet layer.
 17. The closed-loop heat removal system of claim 11, wherein the fluid is water.
 18. A method of removing heat from a portion of a vehicle comprising the steps of: providing a fluid-cooled heat shield comprising a heat sink conductively attached to a conductive sheet layer positioned between an insulating sheet layer and a facing sheet layer; positioning the facing sheet layer of the fluid-cooled heat shield toward a source of heat of the vehicle; pumping a fluid through the heat sink wherein heat from the conductive sheet layer and the heat sink is transferred to the fluid; and pumping the fluid through a radiator wherein the heat is transferred from the fluid to an ambient air.
 19. The method of claim 18, further comprising the steps of: providing a fluid thermal expansion tank; and allowing the fluid to expand in the thermal expansion tank as needed.
 20. The method of claim 18, further comprising the steps of: providing a fan associated with the radiator; and activating the fan to cause air flow through the radiator to transfer heat from the fluid to the air. 